Didi Gregorius and Billy Hamilton both have new teams. (Chris Nelson and Ricky Bassman/MiLB.com)

Readers: Welcome to the second edition of "Transaction Tracker," which will update you weekly on the most notable moves involving prospects in the Minor Leagues. All comings and goings of MLB.com's top prospects are included and are ordered by organization. Questions? Suggestions for improvement? Fill up the comment section below.

Notes: MLB.com's No. 26 prospect climbing a level following a superb first half at Class A Adv. Bakersfield and talkative showing in the Futures Game is this week's most significant transaction. The slight switch-hitter batted .323 and reached base safely in 41 percent of his plate appearances for Blaze prior to his callup. He made 25 errors in 82 games at shortstop and will need to show Cincinnati's brass he can make the routine plays at the infield's most arduous position. If he doesn't, those decision-makers will start to consider utilizing his speed in center field. Hamilton will also be challenged to keep producing offensively in the stingier Southern League, but he has made huge strides since the Reds drafted him 57th overall out of a Mississippi high school in 2009. Hamilton tripled and swiped a base, his 105th overall, in his Blue Wahoos debut on 7/11. This move was made in conjunction with another...

Notes: MLB.com's No. 72 prospect went for 2-for-8 with two strikeouts over four games for the Astros. He had yet to make his debut for the RedHawks since coming over in the 7/4 trade involving veteran slugger Carlos Lee.

Notes: MLB.com's No. 24 prospect compiled a 5.69 ERA and a 1.67 WHIP in 17 Pacific Coast League starts spanning 91 2/3 innings. This, after a 2011 season in which he compiled a 5.32 ERA and a 1.50 WHIP in 28 PCL games spanning 150 2/3 frames. "He's actually throwing fine," Royals general manager Dayton Moore told MLB.com on 7/11. "We just want to get him back there with [pitching coach] Larry Carter and work on some things. The organization just felt it was the right thing to do. Just give him a breather and re-start a little bit." This move was made in conjunction with another...

Notes: MLB.com's No. 82 prospect had been struggling in his first run through the PCL but rebounded with a .336 June batting average and a solid start to July before going down. He has posted .266/.293/.398 marks through 80 games.